Simulation Study On The Electromagnetic Environmental Effects Adaptability And Optimum Structural Design On An Insensitive Electric Primer

In this dissertation,based on a bridgewire electric primer,the semiconductor bridge(SCB)was utilized to replace the bridgewire as the electric primer energy converter with a new packaging structure.The whole process of electromagnetic energy working on SCB electric primer has been simulated by using finite element simulation software.And the influences of the structure parameters on the electromagnetic environmental effects compatibility of SCB electric primer were analyzed and the structure was optimized.Meanwhile,the ignition performance and the electromagnetic environmental effects adaptability of electric primer were investigated by constant current experiment and electromagnetic experimental tests.The main conclusions were as follows:(1)The ansys results showed that the temperature of the bridge area was increasing exponentially in the initial stage under constant current Then the temperature gradually reached a balanced state till the end.It is noted that the explosive and insulation pad were the main medium of heat conduction during the whole process.When the loading condition became electrostatic pulse discharge,it is concluded that the energy cannot be transmitted effectively which resulted from the short electrostatic charging time.The temperature was mainly concentrated in the semiconductor bridge chip,the maximum temperature of the bridge membrane was 378K under the national military standard and 1268K under the.U.S.military standard(2)On the condition of constant current excitation,the maximum temperature of the bridge membrane was decreasing exponentially with the increase of thermal conductivity of the explosive.The ambient temperature has little influence on the temperature variation of chip.The insulation material,which has large thermal conductivity and thin pattern,has better heat dissipating performance.While in the electrostatic discharge mode,explosive,environmental temperature and the properties of insulating materials have no effect on the antistatic ability of electric primer.(3)According to the results from the numerical simulation of bridge temperature,with the increase of coefficient of heat radiation of the material around the bridge,the highest temperature of the semiconductor bridge membrane and the time for reaching the highest temperature decrease exponentially.Environmental temperature mainly influenced the highest temperature of bridge area in the heating process The highest temperature of the bridge area increased linearly and the heating rate of bridge area decreased while the quality of the bridge increased.(4)According to the theoretical simulation results,two different electric primer structures were designed which are Z-type and J-type.the constant current sensitive experiment showed that 50%ignition current of Z-type SCB electric primer was 1.955A and 1.840A for J-type.after the 1A1W5min experiment,the ignition performances of electric primers were different.Z-type SCB electric primer didn't show any significant changes,while J-type SCB electric primer reduced.It is indicated that Z-type SCB electric primer has a better safety performance.(5)The GTEM experiment showed that both types electric primers could keep safety with a 300MHz frequency and 500V/m field strength.However,in the RF injection test,the firing probability of Z-type SCB electric primer is 60%and J-type is 100%with a 750MHz/20W RF energy.It is indicated that Z-type SCB electric primer shows higher capability of anti-RF than J-type SCB electric primer.